xref: /openbmc/linux/drivers/acpi/processor_core.c (revision 8a10bc9d) 
1 /*
2  * Copyright (C) 2005 Intel Corporation
3  * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
4  *
5  *	Alex Chiang <achiang@hp.com>
6  *	- Unified x86/ia64 implementations
7  *	Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
8  *	- Added _PDC for platforms with Intel CPUs
9  */
10 #include <linux/export.h>
11 #include <linux/dmi.h>
12 #include <linux/slab.h>
13 #include <linux/acpi.h>
14 #include <acpi/processor.h>
15 
16 #include "internal.h"
17 
18 #define PREFIX			"ACPI: "
19 #define _COMPONENT		ACPI_PROCESSOR_COMPONENT
20 ACPI_MODULE_NAME("processor_core");
21 
22 static int __init set_no_mwait(const struct dmi_system_id *id)
23 {
24 	printk(KERN_NOTICE PREFIX "%s detected - "
25 		"disabling mwait for CPU C-states\n", id->ident);
26 	boot_option_idle_override = IDLE_NOMWAIT;
27 	return 0;
28 }
29 
30 static struct dmi_system_id processor_idle_dmi_table[] __initdata = {
31 	{
32 	set_no_mwait, "Extensa 5220", {
33 	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
34 	DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
35 	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
36 	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
37 	{},
38 };
39 
40 static int map_lapic_id(struct acpi_subtable_header *entry,
41 		 u32 acpi_id, int *apic_id)
42 {
43 	struct acpi_madt_local_apic *lapic =
44 		(struct acpi_madt_local_apic *)entry;
45 
46 	if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
47 		return -ENODEV;
48 
49 	if (lapic->processor_id != acpi_id)
50 		return -EINVAL;
51 
52 	*apic_id = lapic->id;
53 	return 0;
54 }
55 
56 static int map_x2apic_id(struct acpi_subtable_header *entry,
57 			 int device_declaration, u32 acpi_id, int *apic_id)
58 {
59 	struct acpi_madt_local_x2apic *apic =
60 		(struct acpi_madt_local_x2apic *)entry;
61 
62 	if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
63 		return -ENODEV;
64 
65 	if (device_declaration && (apic->uid == acpi_id)) {
66 		*apic_id = apic->local_apic_id;
67 		return 0;
68 	}
69 
70 	return -EINVAL;
71 }
72 
73 static int map_lsapic_id(struct acpi_subtable_header *entry,
74 		int device_declaration, u32 acpi_id, int *apic_id)
75 {
76 	struct acpi_madt_local_sapic *lsapic =
77 		(struct acpi_madt_local_sapic *)entry;
78 
79 	if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
80 		return -ENODEV;
81 
82 	if (device_declaration) {
83 		if ((entry->length < 16) || (lsapic->uid != acpi_id))
84 			return -EINVAL;
85 	} else if (lsapic->processor_id != acpi_id)
86 		return -EINVAL;
87 
88 	*apic_id = (lsapic->id << 8) | lsapic->eid;
89 	return 0;
90 }
91 
92 static int map_madt_entry(int type, u32 acpi_id)
93 {
94 	unsigned long madt_end, entry;
95 	static struct acpi_table_madt *madt;
96 	static int read_madt;
97 	int apic_id = -1;
98 
99 	if (!read_madt) {
100 		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
101 					(struct acpi_table_header **)&madt)))
102 			madt = NULL;
103 		read_madt++;
104 	}
105 
106 	if (!madt)
107 		return apic_id;
108 
109 	entry = (unsigned long)madt;
110 	madt_end = entry + madt->header.length;
111 
112 	/* Parse all entries looking for a match. */
113 
114 	entry += sizeof(struct acpi_table_madt);
115 	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
116 		struct acpi_subtable_header *header =
117 			(struct acpi_subtable_header *)entry;
118 		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
119 			if (!map_lapic_id(header, acpi_id, &apic_id))
120 				break;
121 		} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
122 			if (!map_x2apic_id(header, type, acpi_id, &apic_id))
123 				break;
124 		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
125 			if (!map_lsapic_id(header, type, acpi_id, &apic_id))
126 				break;
127 		}
128 		entry += header->length;
129 	}
130 	return apic_id;
131 }
132 
133 static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
134 {
135 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
136 	union acpi_object *obj;
137 	struct acpi_subtable_header *header;
138 	int apic_id = -1;
139 
140 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
141 		goto exit;
142 
143 	if (!buffer.length || !buffer.pointer)
144 		goto exit;
145 
146 	obj = buffer.pointer;
147 	if (obj->type != ACPI_TYPE_BUFFER ||
148 	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
149 		goto exit;
150 	}
151 
152 	header = (struct acpi_subtable_header *)obj->buffer.pointer;
153 	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
154 		map_lapic_id(header, acpi_id, &apic_id);
155 	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
156 		map_lsapic_id(header, type, acpi_id, &apic_id);
157 	}
158 
159 exit:
160 	kfree(buffer.pointer);
161 	return apic_id;
162 }
163 
164 int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
165 {
166 	int apic_id;
167 
168 	apic_id = map_mat_entry(handle, type, acpi_id);
169 	if (apic_id == -1)
170 		apic_id = map_madt_entry(type, acpi_id);
171 
172 	return apic_id;
173 }
174 
175 int acpi_map_cpuid(int apic_id, u32 acpi_id)
176 {
177 #ifdef CONFIG_SMP
178 	int i;
179 #endif
180 
181 	if (apic_id == -1) {
182 		/*
183 		 * On UP processor, there is no _MAT or MADT table.
184 		 * So above apic_id is always set to -1.
185 		 *
186 		 * BIOS may define multiple CPU handles even for UP processor.
187 		 * For example,
188 		 *
189 		 * Scope (_PR)
190                  * {
191 		 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
192 		 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
193 		 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
194 		 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
195 		 * }
196 		 *
197 		 * Ignores apic_id and always returns 0 for the processor
198 		 * handle with acpi id 0 if nr_cpu_ids is 1.
199 		 * This should be the case if SMP tables are not found.
200 		 * Return -1 for other CPU's handle.
201 		 */
202 		if (nr_cpu_ids <= 1 && acpi_id == 0)
203 			return acpi_id;
204 		else
205 			return apic_id;
206 	}
207 
208 #ifdef CONFIG_SMP
209 	for_each_possible_cpu(i) {
210 		if (cpu_physical_id(i) == apic_id)
211 			return i;
212 	}
213 #else
214 	/* In UP kernel, only processor 0 is valid */
215 	if (apic_id == 0)
216 		return apic_id;
217 #endif
218 	return -1;
219 }
220 
221 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
222 {
223 	int apic_id;
224 
225 	apic_id = acpi_get_apicid(handle, type, acpi_id);
226 
227 	return acpi_map_cpuid(apic_id, acpi_id);
228 }
229 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
230 
231 static bool __init processor_physically_present(acpi_handle handle)
232 {
233 	int cpuid, type;
234 	u32 acpi_id;
235 	acpi_status status;
236 	acpi_object_type acpi_type;
237 	unsigned long long tmp;
238 	union acpi_object object = { 0 };
239 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
240 
241 	status = acpi_get_type(handle, &acpi_type);
242 	if (ACPI_FAILURE(status))
243 		return false;
244 
245 	switch (acpi_type) {
246 	case ACPI_TYPE_PROCESSOR:
247 		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
248 		if (ACPI_FAILURE(status))
249 			return false;
250 		acpi_id = object.processor.proc_id;
251 		break;
252 	case ACPI_TYPE_DEVICE:
253 		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
254 		if (ACPI_FAILURE(status))
255 			return false;
256 		acpi_id = tmp;
257 		break;
258 	default:
259 		return false;
260 	}
261 
262 	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
263 	cpuid = acpi_get_cpuid(handle, type, acpi_id);
264 
265 	if (cpuid == -1)
266 		return false;
267 
268 	return true;
269 }
270 
271 static void acpi_set_pdc_bits(u32 *buf)
272 {
273 	buf[0] = ACPI_PDC_REVISION_ID;
274 	buf[1] = 1;
275 
276 	/* Enable coordination with firmware's _TSD info */
277 	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
278 
279 	/* Twiddle arch-specific bits needed for _PDC */
280 	arch_acpi_set_pdc_bits(buf);
281 }
282 
283 static struct acpi_object_list *acpi_processor_alloc_pdc(void)
284 {
285 	struct acpi_object_list *obj_list;
286 	union acpi_object *obj;
287 	u32 *buf;
288 
289 	/* allocate and initialize pdc. It will be used later. */
290 	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
291 	if (!obj_list) {
292 		printk(KERN_ERR "Memory allocation error\n");
293 		return NULL;
294 	}
295 
296 	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
297 	if (!obj) {
298 		printk(KERN_ERR "Memory allocation error\n");
299 		kfree(obj_list);
300 		return NULL;
301 	}
302 
303 	buf = kmalloc(12, GFP_KERNEL);
304 	if (!buf) {
305 		printk(KERN_ERR "Memory allocation error\n");
306 		kfree(obj);
307 		kfree(obj_list);
308 		return NULL;
309 	}
310 
311 	acpi_set_pdc_bits(buf);
312 
313 	obj->type = ACPI_TYPE_BUFFER;
314 	obj->buffer.length = 12;
315 	obj->buffer.pointer = (u8 *) buf;
316 	obj_list->count = 1;
317 	obj_list->pointer = obj;
318 
319 	return obj_list;
320 }
321 
322 /*
323  * _PDC is required for a BIOS-OS handshake for most of the newer
324  * ACPI processor features.
325  */
326 static int
327 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
328 {
329 	acpi_status status = AE_OK;
330 
331 	if (boot_option_idle_override == IDLE_NOMWAIT) {
332 		/*
333 		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
334 		 * mode will be disabled in the parameter of _PDC object.
335 		 * Of course C1_FFH access mode will also be disabled.
336 		 */
337 		union acpi_object *obj;
338 		u32 *buffer = NULL;
339 
340 		obj = pdc_in->pointer;
341 		buffer = (u32 *)(obj->buffer.pointer);
342 		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
343 
344 	}
345 	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
346 
347 	if (ACPI_FAILURE(status))
348 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
349 		    "Could not evaluate _PDC, using legacy perf. control.\n"));
350 
351 	return status;
352 }
353 
354 void acpi_processor_set_pdc(acpi_handle handle)
355 {
356 	struct acpi_object_list *obj_list;
357 
358 	if (arch_has_acpi_pdc() == false)
359 		return;
360 
361 	obj_list = acpi_processor_alloc_pdc();
362 	if (!obj_list)
363 		return;
364 
365 	acpi_processor_eval_pdc(handle, obj_list);
366 
367 	kfree(obj_list->pointer->buffer.pointer);
368 	kfree(obj_list->pointer);
369 	kfree(obj_list);
370 }
371 
372 static acpi_status __init
373 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
374 {
375 	if (processor_physically_present(handle) == false)
376 		return AE_OK;
377 
378 	acpi_processor_set_pdc(handle);
379 	return AE_OK;
380 }
381 
382 void __init acpi_early_processor_set_pdc(void)
383 {
384 	/*
385 	 * Check whether the system is DMI table. If yes, OSPM
386 	 * should not use mwait for CPU-states.
387 	 */
388 	dmi_check_system(processor_idle_dmi_table);
389 
390 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
391 			    ACPI_UINT32_MAX,
392 			    early_init_pdc, NULL, NULL, NULL);
393 	acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
394 }
395